Origin & Structure of the Earth

EARTH SCIENCE CHAPTER 1: ORIGIN AND STRUCTURE OF THE EARTH Genesis • • UNIVERSE THEORIE One of the books of the Hebrew Bible and Christian’s Old Testament. Separated light from darkness, created the sky, land, sea, moon, stars, and every living creature in six days. Anaxagoras • Believed in a primordial universe. Leucippus and Democritus • Believed in an atomic universe. Aristotle and Ptolemy • The Greek philosophers proposed a geocentric universe where earth stayed motionless in the heaven, and everything was revolving around it. • • Singularity • • Contradicted the theory of the philosophers (Aristotle and Ptolemy) His theory of heliocentrism demonstrated that the motions of celestial objects can be explained without putting the earth in the center of the universe. Sir Isaac Newton • In 1687, he described the universe as a static, steady state, infinite universe. Albert Einstein • Believed that the universe was static, neither expanding nor contracting but he added a cosmological constant to this general theory. • Attributed the fundamental statement of the big bang theory in 1927. Edwin Hubble • • Supported the theory and he demonstrated the continuously expanding of the universe through the observation of galactic redshifts in 1929. An American astronomer that showed that the universe is not static. Arno Penzias and Robert Wilson • Discovered the cosmic microwave background radiation in 1965. THE FOUR FUNDAMENTAL FORCES Gravity – attraction between bodies Electromagnetic forces – binds atoms into molecules. Strong nuclear force – binds protons and neutrons together in the nucleus. Weak nuclear force – can change a neutron into a proton in a process called nucleus decay. MODERN THEORIES A synthesis of the past observations, theories and laws, as well as the understanding of mass, energy, and relativity. • • The new types of telescopes and sensors, which extended humankind’s ability to observe the further regions of the universe. • BIG BANG THEORY There are only pure energy compresses in a single point when matter was not present. Georges Lemaitre Nicolaus Copernicus • Current accepted model on the formation of the universe. Describes that the universe is expanding, having originated from an infinitely dense point around 14 Gya. OSCILLATING UNIVERSE Cycle of big bang and big crunch. Albert Einstein has favored this model after rejecting his own, this followed general theory or relativity equations of the universe with positive curvature. It resulted in the expansion of the universe for a time and then to its contraction due to the pull of gravity. STEADY STATE THEORY EARTH SCIENCE CHAPTER 1: ORIGIN AND STRUCTURE OF THE EARTH • • • • • • • • Proposed by astronomers Fred Hoyle, Thomas Gold, and Hermann Bondi. Predicted a universe that expanded but did not change its density – matter was inserted into the universe. INFLATIONARY UNIVERSE Alan Guth – American physicist, he incorporated a short early period of exponential cosmic inflation to solve the uncertainties of the standard big bang model. Became known as inflationary model. • • • Rogue star material is less dense and becomes outer Solar System planets Inner Solar System material is denser and becomes terrestrial planets. MULTIVERSE Multiple universe Theory that not only one universe exists, that many universes are out there and may or may not be different from our laws of nature. PRIMORDIAL UNIVERSE Theory before the big bang Before or the beginning of time. THE ORIGIN OF THE SOLAR SYSTEM • The solar system is in the Milky Way galaxy – a huge disc and a spiral-shaped aggregation of about at least 100 billion stars and other bodies. • Gas is tidally removed from both rogue star and Sun • • • ENCOUNTER HYPOTHESIS One of the earliest theories for the formation of the planets. In this scenario, a rogue star passes close to the Sun about 5 billion years ago. Material, in the form of hot gas, is tidally stripped from the Sun and the rogue star. This material fragments into smaller lumps which form the planets. Self-gravity contracts a gas cloud. Conservation of angular momentum pulls cloud into a disk. Disk begins to rotate. This hypothesis has the advantage of explaining why the planets all revolve in the same direction (from the encounter geometry) and provides an explanation for why the inner worlds are denser than the outer worlds. Central mass form (proto-sun) • Rogue star passes close to the Sun NEBULAR HYPOTHESIS In this theory, the whole Solar System starts as a large cloud of gas that contracts under self-gravity. Conservation of angular momentum requires that a rotating disk form with a large concentration at the center (the proto-sun). Within the disk, planets form. Spinning cloud of dusk, nebula, flattened into a disk, and became a solar system consisting of a star with orbiting planets. • Centrifugal force balances gravitational forces and a ring Ring forms into forms. planets. PROTOPLANET HYPOTHESIS The current working model for the formation of the Solar System. It incorporates many of the components of the nebular hypothesis but adds knowledge of fluids and states of matter. EARTH SCIENCE CHAPTER 1: ORIGIN AND STRUCTURE OF THE EARTH 1 2 3 4 5 6 •orion arm starts to contract due to gravity •as most becomes proto-sun, the remainding will form a disc-planets. •fragments from large bodies due to collision •high speed collisions destroys much of the mantle of Mercury. puts Venus in retrogade rotation •collision of earth with a large object produces moon •when the proto-sun is established as a star, its solar wind blasts hydrogen etc to form the gas giants. LIFE ON EARTH The presence of liquid water, heat source and air or atmosphere make the earth suitable for life. HABITABLE ZONE Also known as the Goldilocks zone. It provides just the right amount of heat and the capacity to maintain water in its liquid form. HEAT SOURCE Temperature influences how quickly atoms and molecules move. Life sees to be limited to a temperature range of -15 degrees Celsius to 115 degrees Celsius. In this range, liquid water can still exist under certain conditions. • • Internal heat source External heat source ATMOSPHERE Earth’s atmosphere is about 100 miles thick. It keeps the surface warm, and protects it from radiation, and small to medium sized meteorites. LAYERS OF EARTH’S ATMOSPHERE Exosphere – 1200 degrees Celsius. 800 to 3000 km Thermosphere – -86,5 to 1200 degrees Celsius. 80-90 to 800 km Mesosphere – -2,5 to -86,5 degrees Celsius. 4050 to 80-90 km Stratosphere – -56,5 to -2,5 degrees Celsius. 11 to 50 km Troposphere – 15 to -56,5 degrees Celsius. 0 to 12-18 km EARTH’S SUBSYSTEM The interaction among Earth’s subsystems is vital in sustaining life on the planet. Earth is a closed system. Energy in the form of solar radiation passes from the sun, through the atmosphere to the surface. The earth in turn emits radiation back out of space across the system boundary. Hence, energy passes across the earth’s system boundary but not mass, making it a Closed System. • Biosphere • Atmosphere • hydrosphere • geosphere These four systems are linked system, any changes in one system affects the other three. Geosphere • • Refers to the solid earth, the rocks, minerals, and geologic landforms on Earth. Composed of naturally occurring solid aggregate of minerals, organic materials called rocks. Hydrosphere • • The totality of Earth’s water The frozen part of the water is called cryosphere. Atmosphere • • Extends to about 10km about earth. Composed of 78% nitrogen, 21% oxygen, 0.9% argon, and 0.1% carbon dioxide and for other gases, including water vaper that surround the earth. Biosphere • Made up of the parts of earth where life exists.